Organosilicon compounds and processes for producing the same

ABSTRACT

HOMOPOLYMERS OF THE FORMULA   X-CO-CH2-CH2-SI(-R&#39;&#39;)-(O)((3-B)/2)   AND COPOLYMERS CONTAINING THE ADDITIONAL UNIT (R&#34;)D-SI-O(4-D)/2 USEFUL TO COMBINE WITH ALKYL RESINS TO MAKE HEAT RESISTANT COATINGS FOR GLASS CLOTH, ALUMINUM AND SHEET STEEL, WHERE X IS CL, ZHN, OR MO; Z IS R&#39;&#39;, NH2 SUBSTITUTED MONOVALENT HYDROCARBON, OR COOH SUBSTITUTED MONOVALENT HYDROCARBON; M IS ALKALI METAL, AND R&#39;&#39; IS MONOVALENT HYDROCARBON RADICAL, ARE DISCLOSED.

Ki l 396299339 3 629,309 ORGANOSILICON COMPOUNDS AND PROCESSES FORPRODUCING THE SAME -Donald L. Bailey, Sistersville', W. Va., and VictorB Jex,

Scarsdale, N.Y., assignors to Union Carbide Corporation, New York, N.Y.

No Drawing. Continuation-impart of application Ser. No. 615,492, Oct.12, 1956. This application Nov. 13, 1969, Ser. No. 876,567

Int. Cl. C07b 7/08, 7/10; C07h 7/18 'U.S. Cl. 260-448.2 B 12 ClaimsABSTRACT OF THE DISCLOSURE Homopolymers of the formula and copolymerscontaining the additional unit R" 1Sl0f1 d CROSS-REFERENCE TO RELATEDAPPLICATIONS This application is a continuation-in-part of Ser. No.615,492 filed Oct. 12, 1956, now US. Pat. No. 3,493,533.

This invention relates in general to the synthesis of organosiliconcompounds. More particularly, the invention contemplates the provisionof new organosilane and organo-siloxane derivatives containing, amongother possible functional groups, a carboxy or carboalkoxy functionalgroup which is linked to the silicon atom or atoms through an aliphatichydrocarbon substituent in a position removed from the silicon nucleusby at least two carbon atoms of the aliphatic linkage, i.e.,beta-substituted or further along a silicon-bonded polymethylene chain.The invention further contemplates the provision of unique processes forproducing compounds of the general class described as well as usefulderivatives of such compounds.

Heretofore, organosilicon compounds containing silicon-substitutedcarboxylated radicals have been produced by reacting, in the presence ofa. peroxide catalyst, unsaturated aliphatic or cyclic monoesters anddiesters with halogen-, hydrocarbon-, or halogenatedhydrocarbon-substituted silanes containing at least one silanic hydrogenbond, to provide a carboxylated silane which is then hydrolyzed toproduce a corresponding siloxane. While the foregoing technique has beenapplied largely in connection with the cyclic esters, it has beenpostulated by at least some investigators that the process isunsatisfactory when applied to aliphatic and cyclic unsaturated estersin which the unsaturated linkage is so positioned that a functionalcarbonyl group will be positioned less than three carbon atoms from thesilicon nucleus following the ester-silane reaction, as would be thecase, for example, when esters of acrylic acid are employed as startingmaterials. That is to say, it would appear from available literaturereports that the process is inherently limited to the production ofsilanes and siloxanes in which the carboxy or carboalkoxy substituentsare positioned no closer to the silicon atom than the gamma carbon I3,629,309 Ffat nted'Dee. 21, 1971 I alcoholysis of cyanoalkyl siliconcompounds, whereby the cyano group (CN) of the cyanoalkyl substituent isconverted to the; desired carboalkoxy substituent, as represented ingeneral by the following equation:

wherein R represents a monovale'nt hydrocarbon radical, including bothalkyl and aryl radicals, and a may be any number greater than one.Whereas any strong mineral acid may be employed as catalyst in thealcoholysis reactions of the invention,we prefer to employ hydrochloricacid as depicted within the foregoing equation because of its case ofremoval as compared, for example, with sulfuric acid.

The basic reaction of the invention as illustrated above is equallyapplicable to the cyanoalkylsilanes, cyanoalkylalkoxysilanes andcyanoalkylsiloxanes. Thus, suitable cyanoalkyl monomeric and polymericstarting materials for use in the process of the invention may berepresented in general by the following'formulae:

(A) Rb NC (CH2) as X(ab) and wherein R represents any monovalenthydrocarbon radical, including both alkyl and aryl radicals; Xrepresents halogen or alkoxy; a any number greater than one; b inFormula A has a value from 0 to 3 inclusive, and in Formula B a valuefrom 0 to 2 inclusive; and n in Formula B may be any whole numbergreater than one. Cyanoalkyl compounds of the general class definedabove and process for their production have been described and claimedin copending US. application Ser. No. 555,201, filed jointlyby Victor B.Jex and]. E. McMahon on Dec. 23, 1955, now US. Patent 3,257,440 and Ser.No. 555,203, now abandoned, filed jointly by Victor B. Jex and R. Y.Mixer, also on Dec. 23, I955.

The process of the invention is particularly useful in the preparationof carboalkoxy-substituted compounds, and is unique in its applicationto the production of the carboalkoxyalkyldialkylalkoxy-,carboalkoxyalkylalkyldialkoxyand carboal-koxyalkyltrialkoxysilanemonomers as represented in general by the following formula:

wherein Rand'R' represent monovalent hydrocarbon radicals; Xrepresents'alkoxy; a is any number greater than one; and bhas a valuefrom 0 m2 inclusive.

The above-ind'cated compounds are prepared by esterification of theaanoa'lkylchlorosilanes and subsequent acid-catalyzed alcoholysis of thecyano group as per Equation I aboveThe process is most convenient sincethe ester is formed initially and the hydrogen chloride evolved in itsformation may be utilized in the subsequent alcoholysis reaction. Ingeneral, the combined reaction is effected by placing the particularcyanoalkylchlorosilane starting material within a suitable reactionvessel fitted with a stirrer, thermometer, reflux condenser and droppingfunnel. Absolute alcohol is then added to the reaction vessel withstirring and the hydrogen chloride evolved by thereaction is passed fromthe vessel. When one, two or three equivalents of alcohol have beenadded, depending upon whether the starting material is a mono-, di-, ortrichlorosilane, approximately a three molar excess of alcohol over thatrequired for alcoholysis of the nitrile group is added, and the solutionis heated to the reflux temperature. The solution is refluxed forseveral hours during which time ammonium chloride is formed. The mixtureis then filtered, and the excess alcohol removed by a suitable vacuumevaporation technique. The resulting carboalkoxylylalkoxysilane is thendistilled to yield the pure compound.

We have found that while theoretical quantities of alcohol and hydrogenchloride can be used in the process of the invention, it is generallybest to employ a two or three molar excess of alcohol, and to maintainthe solution substantially saturated with hydrogen chloride during thealcoholysis reaction. The reaction is conveniently conducted at therefluxing temperature of the alcohol employed, usually at temperatureswithin the range 50110 C. for the more common aliphatic alcohols such asmethanol, ethanol propanol, butanol, etc., but higher temperatures canbe employed. Significantly, We have found that substantially increasedyields can be obtained by conducting the alcoholysis reaction underpressure, and such a procedure is advisible or large scale commercialoperations.

The monomeric alkoxy-substituted silanes as represented by Formula (C)above are readily hydrolyzed and condensed to the siloxanes, and, in thereaction, the carboalkoxy group may be preserved or hydrolyzed to acarboxy group. Thus, for example, the following equation represents atypical reaction for the production of a can boxy-substitutedpolysiloxane by hydrolysis of a trifunctional carboalkoxy silane in thepresence of a strong acid (HCl), wherein H and a have the meaningsassigned above and n is any number greater than one:

ltoocxormflsuonn 1120 Pg [I100C(cH2)uS 03/2]u Roll In the absence ofmineral acid, the silane monomers may be hydrolyzed to produce cyclicsiloxanes Which retain the carboalkoxy organo functional group, asrepresented in general by the following equation illustrating thehydrolysis of a silicon difunctional carboalkoxy silane, wherein R, Rand a have the meanings assigned above and n is any number greater thantwo: (III) R R BOOC(CH2),.S1(0R)2 Hi [ROOC)CI-Iz),.SiO]n ROI-IAlternatively, we may effect the direct acid-catalyzed alcoholysis of acyanoalkyl siloxane (Formula B above) With conversion of the cyano groupto produce a core sponding carboalkoxy siloxane derivative of linear orcyclic structure depending on the starting material employed, asrepresented by the following equation, wherein R, R'a and n have themeanings previously assigned above:

(IV) R [CN(C lIzhSiOL. llUl R011 be subjected, also, totransesterification to produce modified carbofunctional silicone esters.Thus, the carboalkoxy- 4 alkylalkoxysilanes and carboalkoxyalkylsiloxanes obtained by the foregoing basic reactions may betransesterified in the presence of an acid catalyst to produce siliconeesters of the types represented by the following formulae:

I b [R 0 0C (CHzMSiO etc.

wherein R, R, a, b and rz have the meanings previously assigned above,and R" represents a monovalent hydrocarbon radical.

The alcohols used in the transesterification reaction may be any of thealiphatic primary, secondary or tertiary alcohols, or hydroxy-endblockedpolypropylene or polyethylene oxide polymers, or, aromatic hydroxycompounds such as phenol may be employed. When carrying out thetransesterification reactions, we prefer to employ anhydrous conditionsinasmuch as the esterification is a reversible reaction. In the case ofthe carboalkoxyalkylalkoxy silanes anhydrous operations are necessary inorder to prevent the formation of Si-OfiSi bonds by hydrolysis. Theratio of the reactants is not critical in the reaction, and in fact, wehave found that even with molar ratios of less than one alcohol groupper alkoxy group, some transesterification takes place although theendproducts under such conditions are usually mixed compounds. We havefurther found it to be possible, by use of controlled amounts ofalcohol, to transesterify only the carboalkoxy group while retaining anysiliconalkoxy bonds unchanged, as represented by the compounds ofFormula E above. When complete transesterification is sought, it isdesirable to use one mole of the alcoholic reagent for each alkoxy groupin the molecule, and, if a relatively volatile alcohol is used, toemploy a slight excess as in the case of .the basic alcoholysis reactiondescribed hereinbefore.

Any strong acid may be used to catalyze the transesterification reactionalso, but we prefer to employ acids such as trifluoroacetic,perfluoroglutaric or any perfluoro organic acid or hydrogen chloride,since such acids are readily removable from the reaction system. Thereaction may be effected at temperatures Within the range 60-250 C.While We have employed temperatures within the range 60200 C. for thereaction when a catalyst such as trifluoroacetic acid was used,temperatures within the range ZOO-250 C. have been employed withsatisfactory results. While the transesterification reaction may beeffected under pressure also, this practice merely serves to raise thereaction temperature. In actual practice, We prefer to operate atatmospheric pressure so that the more volatile alcohol may be removed,thereby driving the reaction to completion. Furthermore, While thereaction may be effected in solvents such as benzene, toluene, xylene,etc., With the advantage of raising and permitting control of thetemperature at reflux and thereby facilitating the removal of the morevolatile alcohol, we have found that the reaction may be controlledadequately in the absence of any solvent and prefer to operate in thismanner.

In general, the carboalkoxyalkylalkoxysilane monomers of the inventionwill undergo all of the usual reactions of organic esters andalkoxysilanes to yield a variety of silicone products. The silanes aregenerally Water-white liquids. The trifunctional silanes in particularare thermally stable on distillation at atmospheric pressure-little orno loss occurring due to cleavage or polymer formation. The silanespossess long shelf-life provided they are stored in a closed system, andare relatively light stable, in that, no darkening or polymer formationcan be de tected when the materials are stored in covered containers.The alkoxy groups attached to the silicon nucleus hydrolyze in thepresence of moisture in a manner similar to conventional alkoxysilanederivatives, On treatment with excess water the compounds yieldhydrolyzates by reaction of their silicon-bonded alkoxy groups whichvary in composition from viscous, colorless oils to aqueousalcoholicsolutions of the corresponding polysiloxanes. These hydrolyzates may beconcentrated to yield resins. The addition of small amounts of water tothe compounds yield intermediate liquid hydrolysis products of varyingcompositions. The hydrolysis reactions can be controlled to efiectcomplete or partial hydrolysis such that the re-= sulting compounds willcontain some residual alkoxy The siloxanes of this invention includethose represented by the formula:

wherein R is a member selected from the group consisting of hydrogen andmonovalent hydrocarbon radicals; R and R" are members selected from thegroup consisting of monovalent hydrocarbon radicals; R" is a memberselected from the group consisting of alkoxy and monovalent hydrocarbonradicals; and x and y are whole numbers.

The polysiloxanes prepared from the silane monomers of the invention areextremely useful in the production of a variety of carboxy-andcarboalkoxysiloxy-modified silicone and organic products. They may becopolymerized with other siloxanes of the general unit formulation:

wherein at has a value from 1 to 3 inclusive, and R" represents anymonovalent hydrocarbon radical. The copolymerization can be effected inconventional manner as, for example, by cohydrolysis of thecorresponding hydrolyzable silanes as illustrated above (Equations V andVI), or by catalytic copolymerization of the siloxanes, per se, in thepresence of a siloxane bond-rearranging catalyst. A typicalequilibration of the general class described is that represented by theproduction of carboalkoxypolymethylenealkylsiloxy modified silicone oilsfrom the hydrolyzates 0t carboalkoxypolymethylenealkyldialkoxysilanes,or the corresponding, cyclopolysiloxanes,

with other silicone cyclicsvand a suitable endblocker, in

the presence of acid catalystsias, for'example, the equilibration ofgamma carbethoxypropylmethylsiloxane cyclic tetramen:dodecamethylpentasiloxane, dirnethylsiloxane cyclic tetramerand'sul-furic. acid, toyieldthe carbethoxy-modified dimethylsiliconeoil; represented by the equation:

(VII) Of course, depending'upon the ratio of reactants em ployed; onemay. obtain a variety of. oils of. varying molecular weights andpercentages ofcarboalkoxy. substituents, and oils containing phenyl;ethyl; vinyl and other groups may. be prepared in a similar. manner.Alternatively, in the absence ofthe endblocking polymer one may prepare.a variety of, silicone gumstock polymers.

The hydrolyzates of the carboalkoxyalkylalkoxysilane monomers of theinvention may be readily converted into.

thecorresponding acid salts by. saponification with-base as represented:in general by the following equation illustrating the aqueous alkalisaponification'of a typical The acid salts thus produced. arewatersoluble materials. The free acids are readilyv obtainable byneutralization of the salts with a strong. acid, andthe silicone acidsprepared in this manner can be reacted with thionyl chloride, forexample, to produce the corresponding acid chlorides which undergoreactions typicalof organic acid chlorides.

Apart from the transesterification and saponification reactionsillustrate'dabove, the carboalkoxy groups of the. silane monomersmay bereacted with primary aliphatic or aromatic monoor diamine, such asn-butylarnine, propylene diamine and p-aminobenzoic acid, to 'yieldamide derivatives, as represented. in general by thefollowingequationillustrating the reaction of a typical silanc of the inventionwith a primary amine:

glycols which are found to be good lubricants. Certain.

of these products are included v within the examples which are presentedhereinafter for purposes of illustrating the utility of the end-productsof the present invention, but reference should be had, also, to outcopending applications Ser. Nos. 615,468 new U.S. Pat. 2,957,899 and615,499, now abandoned; both filed Oct. 12, 1956, wherein we havedescribed and claimed other silicone products as well as certain of thelinear and cyclic siloxanes which can be produced by application of theprinciples and techniques of the present invention.

Preferred silanes of this invention include silanes repwherein W is R, aNH substituted monovalent hydrocarbon radical, or a COOH substitutedhydrocarbon radical; R is a monovalent hydrocarbon radical; and b has avalue from to 1 inclusive.

resented by the formula: 5 The siloxane acid chlorides included withinthe scope ROOC(CH2)aSiX3 (i) of Formula iii above can be morespecifically defined as wherein R is a monovalent hydrocarbon radical; Xis an slloxanes compnsmg umts of the formula: alkoxy radical; and a isan integer from 2 to 5. The silanes represented by Formula i includecarboalkoxypolymethyylenetrialkoxysilanes (e.g.,gamma-carbethoxypropyltri- CIOMCHMH ethoxysilane) and silanesrepresented by the formula: 2 (v) ROOC(CHZ)2S1X3 wherein R is amonovalent hydrocarbon radical; and b wherein R 18 a monovalenthydrocarbon radical; and X h avalue f 0 to 1 inclusive all alkOXYl'adlcal- Silanes lePfesentelfl y Formula 11 5 The siloxane saltsincluded Within the scope of Formula Includebeta-Garboalkoxyethylll'lalkoxysllanes Such as iii above can be morespecifically defined as siloxanes beta-carbethoyethyltrleth(fl/$113116comprising units having the formula:

Preferred slloxanes of this 1nvent10n includes s1loxanes comprisingunits of the formula: 1'11,

20 Mo0c oH, ,sio BOC(CH2)2S1OH T (iv) 2 l" wherein B is Cl or W iswherein M 1s an alkali metal, R 1s a monovalent hydrostituted monovalenthydrocarbon radical, or a 'COOH carbon raqlcal and b.has a value 0 1mcluswe' substituted monovalent hydrocarbon radical; M is an aloneVanety q u Slloxane? compnsmg E i represqm' kali metal; is a monovalenthydrocarbon radical; and ed by Formulaan above are siloxanes consistingessentialb has avalue from on) 1 inclusive 1y of such units and unitsrepresented by Formula G The siloxane amides included within the scopeof Forw? h t f f h b h mula iii above can be more specifically definedas simm W eel-tam? t e aslc processes 0ft e loxanes comprising unitsofthe formula: invention as described herembefore, as well as theendproducts derived thereby, are summarized graphically within thefollowing reaction chart wherein silicon trifunc- WHNOC(CHZ)ZS1O3 btional compounds have depicted for purposes of illustra- T (W) tion on aunit formula basis:

REACTION CHART NC(Cl-l SiX or NC(CH SiO ROH H RO0C(CH) Si(OR) l 2 NaQHROOG CH 8110 aooc ca s10 Z a 3/2 R"0OC(CH Si(OR R and R In monovalent:

hydrocarbon X-halogen or alkoxy M2 or more and the other conventionalorganic diluents generally employed in the overbasing procedures of theprior art. Preferably, the diluent selected will be oil-soluble.

A preferred diluent will comprise mineral oil and at least one otherdiluent which is soluble in mineral-oil but about 50% by weight of thetotal weight of starting materials used in the process, particularly inpreparing products having metal ratios in excess offivegThe less viscousdiluents facilitate filtration and for somereason, improveoil-solubility of the final basic magnesium product. That is, thetendency for solids to precipitate during long-term storage is reducedor eliminated. Furthermore, in the absence of these less viscousdiluents, there is a tendency in some instances, particularly inpreparing products of higher metal ratios (e.g., metal ratios in excessof five) foranzunfilterable gel-like mass to form. While such gels :canbe used as basic magnesium components in greases or as anti-rust,anti-corrosion protective coatings .(usually 0.5 to mil thickness) onferrous metalsurfaces exposed to air, moisture, and/or acidic vapors,they are not ordinarily suitable as fuel and lubricating on additives.

In one aspect of this invention, it is preferred that the less viscousdiluent used in combination with mineral oil will have a boiling pointhigher than 75 C. and preferably higher than 90 C. This is intheprocesses usingan alcohol-water promoter where carbonation is conductedfirst in the presence of 'alcohol and water and thenin the presence ofwater. For best results, it has been determined that carbonation in thepresence of water alone should beat a temperature of at least about75'C..and preferably .at least .about 90 C. Since it is convenient toconduct carbonation at the reflux temperature, .diluents having boilingpoints of at least about 75 C. at standard pressure are preferred. Forthis reason, xylene is a particularly preferred diluent since itforms anazeotrope with water boiling at 90-95 C. It offers theadditionaladvantage of assisting in the ..removal of water uponcompletion of theprocess.

In its broadest aspect, the process of this invention involves mixingthecomponents of the reaction mixture, that is, the acids or other suitablederivatives thereofas discussedabove, active magnesium oxide, water, anddiluent and introducing into this reaction mixture at least oneinorganic acidic material. The temperature at which the acidic materialis contacted with the remaining components of the reaction mass is notcritical. Thus, the minimum temperature is that temperature at whichthe, reaction mixture remains fluid, that is, does not begin tosolidify. The maximum temperature is the decomposition temperature ofthe reaction component or product'withtheilowest decomposition point.Usually, the temperature will be in the range of about 200 C. andpreferably'about 150 C. The acidic material is conveniently contactedwith the components of the reaction-mixture at the reflux temperature.The reflux temperature obviously depends upon that material having thelowest boiling point. Accordingly, where methanol is used as a promoterincombination with water, the reaction mixture willbe contacted'with theacidic material at the reflux temperature of methanol. lf water isthe-only promoter and the component ofthe reaction mixture having thelowest boiling point, the reflux temperature will be the boiling pointof water or an azeotrope of water with, for example, xylene.

Generally, the acidic material :is contacted with the components of thereaction mixture until there is no further reaction between thecomponents of the reaction mixture and the acidic :material that is,until'reaction :between :the. components of the reaction mixture and theacidic material substantially ceases. This can'be determined inanumberof ways conventional in the art. For example, if the acidicmaterial is -a gas which is being bubbled through .the reaction mixture,then this end point is reached when the amount of gas being blown intothe mixture substantially equals (that is, corresponds .to about %-100%)the amountof gas leaving the reactionwmixture. This is readilydetermined by the 'use of metered inlet and outlet valves for the gas.The end' point can also be ascertained by periodic measurement of the pHof the reaction mixture. At the point at .until there is no furtherreaction, useful basic magnesium salts can =bepreparedwhen the reactionmixture is contacted with the acidic material for a period of timesufficient for-about 70% of the total acidic material to rev actrelative to the amount which would react if the re- :action werejpermittedcto-proceed to its end point as .described above.

Uponcompletion of the reaction between the acidic material and thecomponents of the reaction mixture, the solid components of the reactionproduct are usually rcmovedby filtration, centrifugation or otherconvenient means. Thereafter, the reaction product is stripped, gen-.erally'atreduced pressure, to remove alcohol, water, and, if desired,.diluent having a boiling point less than mineral oil. Obviously,thereaction mixture can be stripped prior to removing solids.iffdesired.

The foregoingprocedure preferably is modified in the manner explainedbelow if'it is desired to prepare a :basic magnesium salt having a metalratio in excess of about 5 or 6. -In this modified procedure, alcoholmust 'be used as-a co-promoter with the water. The reaction componentsare mixed together and this reaction mixture is then contacted'with theacidic material in two stages.

First, the .componentsof the reaction mixture and the acidic materialare contacted in the same manner as .described above until the reactionbetween the inorganic .acidic material. and the reaction mixturesubstantially ceases. Thereafter, the temperature of the reactionmixtureis raised to remove substantially all free alcoholpromoter. It ispreferable to continue contacting the acidic material with the reactionmixture during this period of time that ;-the alcohol promoter is beingremoved although thisis not essential. Any water that is removed'duringthe'removal of the alcohol is preferably replaced at this point.The reaction mixture with substantially all free alcohol removed is thencontacted with the more acidic material, usually until the liquid phaseof the :reactionsmass becomes substantially clear. Thereafter, the.reaction mass is generally filtered, etc., to removesolidsandthe wateris removed by heating, generally at reduced pressures. Again, ifdesired, any lowboiling1diluent can-also be removed at this point. Asmentioned hereinbefore, this two-stage procedure for contacting thereaction mixture with the acidicma- 'terial results rinproducts'havinglittle or no haze and which are more easily filtered. Moreover, basicmag nesiumsaltshavingmetal ratios in excess of about 5 have improvedoilsolubility-when they are prepared by this two-stage process.

In some instances, thereaction mixture thickens when .the alcoholpromoter is removed. In-those cases, it is preferable thatthe reactionmixture be contacted with .theacidic-material .for a suflicient periodof time for the mixture to again become thinner or less viscous. The forthe thinning of the. r with the continued contuc'.g' with it prepared asdescribed above and then this basic magnesium salt should be employedwith additional magnesium oxide, promoter, and the like to increase themetal ratio. In this manner, the metal ratio of the basic magnesiumsalts can be increased to about 30 or more. Usually, when the metalratio is being increased by conducting the overbasing process in aseries of two or more steps, the metal ratio is usually increased inincrements of about to 15 and preferably in increments of about 8 to 12.Thus, if in the first step, a basic magnesium salt having a metal ratioof 10 is prepared and thereafter used as a starting material in a secondstep of the procedure, sufficient additional magnesium oxide will beadded to provide a sufiicient amount of magnesium to increase the metalratio of the resulting product to about to about 25. Obviously, themetal ratio can be increased by smaller units but this is ineificient.On the other hand, trying to increase the metal ratio by largerincrements increases the tendency of the product to form a haze or togel.

In these modified versions of the process of the present invention, thatis, where the reaction mixture is contacted with the acidic material intwo stages, it is essential for optimum results that the acidic materialbe contacted with the reaction components at a temperature of at leastabout 75 C. and preferably at a temperature of at least about 90 C.after removal of the alcohol promoter. As the free alcohol must beremoved in these modified procedures, it is obvious why it is desirablethat the alcohol promoter used in combination with water have a boilingpoint less than that of water. Otherwise, it is necessary to remove .thewater as well as the alcohol and then add water back to the mixture.Likewise, as explained above, the 'acidic material should be contactedwith the remaining components of the reaction mixtures at temperaturesof least about 75 C. Accordingly, if any diluent of the mixture has aboiling point of less than this, it interferes wvith achieving thistemperature. Increased pressure in such nstances would permit elevationof the temperature but is easily avoided by selecting diluents havingboiling points of at least 75 C. The maximum temperautre is limited onlyby the decomposition temperature of the reactants and product asexplained above but usually will not exceed 200 C. Temperature of 90150C. are preferred.

In a further modification of the process, it has been found useful toemploy a combination of at least one oilsoluble aliphatic carboxylicacid and one other oil-soluble acid of the type described hereinabove toprepare basic magnesium salts. Thus, an organic acid mixture comprisingat least one oil-soluble aliphatic carboxylic acid or other suitablederivative thereof as described above with at least one other organicacid susceptible to overbasing of the types described in detailhereinabove, e.g., on alkylated salicylic acid, a petrosulfonic acid, oran acid prepared from the condensation of phosphorus pentasulfide andpolyisobutylene having a molecular weight of about 1000, is usedaccording to this further modification as the organic acid" to beoverbased. Ordinarily. the aliphatic carboxylic acid per se or itsalkali or alkaline earth metal salts inclding magnesium salts will beused. This modificu tion can be used effectively with water andalcohol-water promoter systems. Generally, the aliphatic carboxylic acidor derivative thereof is employed in an amount such tha there is oneequivalent of the oil-soluble aliphatic carboxylic acid for each one totwenty, usually one to ten equivalents of the other organic acidspresent in the mixture, that is, an equivalent ratio of aliphaticcarboxylic acid to other acid of about 1 :1 to about 1:20 but generally1:1 to about 1:10. The preferred ratio in the case of a combination ofaliphatic carboxylic acids and sulfonic acids is an equivalent ratio ofabout 1:2 to about 1:5. The combination of acids results in a moreefficient utilization of the magnesium oxide although the reason is notknown.

It has also been determined that the presence of at least oneoil-soluble sulfonic acid or suitable derivative thereof susceptible tooverbasing, as described hereinbefore, is beneficial to the efficientutilization of magnesium and the preparation of products having highermetal ratios when preparing basic magnesium salts of at least oneoil-soluble aromatic carboxylic acid or suitable derivatives thereofsusceptible to overbasing such as those illustrated by Formulae I-III.This modification is very useful in preparing basic magnesium salts ofhydroxy-substituted aromatic acids such as salicyclic acids. Thesehydroxysubstituted aromatic acids are exemplified by those includedwithin Formulae II and III. This combination of acids can be usedadvantageously with water as the only promoter or in an alcohol-waterpromotor system as described above. The sulfonic acid may be analiphatic, cycloaliphatic, or an aromatic sulfonic acid or mixtures oftwo or more such acids or derivatives thereof susceptible to overbasing,especially those sulfonic acids illustrated by Formulae IV-V. The amountof aromatic carboxylic acid and sulfonic acid, or their suitablederivatives, used in combination is such that the ratio of equivalentsis about 1:1 to about 20:1, preferably about 2:1 to about 15:1.

A preferred process for overbasing a combination of hydroxy-substitutedaromatic carboxylic acids as described in the preceding paragraphcorresponds to that desired above for overbasing the combination oforganic acids and aliphaict carboxylic acids discussed hereinbefore.This preferred process comprises preparing basic magnesium salts bycarbonating 'a mixture comprising (a) M equivalents of at least onemember selected from oil soluble hydroxy-substituted aromatic carboxylicacids or equivalent derivatives thereof susceptible to overbasing, (b) Nequivalents of at least one member selected from oilsoluble sulfonicacids and equivalent derivatvies thereof susceptible to overbasing, (c)Qequivalents of basically reacting magnesium oxide where the ratio of M:N is about 1:1 to about 20:1 and the value of is from about 1.1 toabout 30 or more, usually not more than 20, and preferably about 2 toabout 12 (d) water and (e) a substantially inert organic liquid mediumuntil the reaciton between the carbon dioxide and the mixturesubstantially ceases. The modifications, variations, and preferences inthe magnesium overbasing processes described herein are also applicableto the overbasing of M and N. Thus, aliphatic alcohols such as methanolor mixtures of methanol and other lower alkanols can be used ascopromoters. However, these co-promoters ordinarily may be deletedwithout adverse results (e.g., haze, gel formation) when preparing basicmagnesium salts from oilsoluble hydroxy aromatic acids or theirderivatives susceptible to overbasing. Likewise, xylene is a preferreddiluent, the metal ratio is usually increased in increments of 5 to 15,the acids per se or their alkali or alkaline earth metal salts ormixtures thereof are usually employed as starting materials and soforth. Further, the process can 3 Example VIII Preparation ofgamma-carbethoxypropylmethylsiloxane cyclic trimer,gamma-carbethoxypropylmethylsiloxane cyclic tetramer, andgamma-car]:ethoxypropylmethylsiloxane cyclic pentamer by acidalcoholysis of gamma-cyanopropylmethylsiloxane cyclic tetramer:

(CHART REACTION 5) Gamma-cyanopropylmethylsiloxane cyclic tetramer, inamount 470 grams, was dissolved in absolute ethanol (552 grams) within athree-liter, three-necked flask fitted with a stirrer, gas inlet tubeand reflux condenser. The solution was then stirred, saturated withhydrogen chloride and heated to reflux (80 C.) for16 hours during whichtime. ammonium chloride precipitated. The ammonium chloride was filteredoff, and the filtrate was again saturated with hydrogen chloride andrefluxed an additional eight (8) hours, at which point it was againfiltered to remove any ammonium chloride; The alcohol was then removedby vacuum evaporation and the residue was washed with dilute sodiumbicarbonate. The siloxane was then dissolved in ether and toluene andwashed with distilled water until neutral to pH paper. The solvents werethen removed by vacuum evaporation. Infrared analysis of the materialshowed it to be high in linear gamma carbethoxypropylmethylpolysiloxanebut free of ,@ONH C=NH and CEN bonds. The following procedure wasadopted to increase the yield of cyclics.

The gamma-carbethoxypropylmethylsiloxane linears, in amount 350 grams,were dissolved in 500 cubic centimeters of toluene within a two-literflask fitted with a reflux condenser, and concentrated sulfuric acid(4.0 grams) was added. The solution was then refluxed for five (5)hours, thereafter cooled to room temperature, and the sulfuric acidneutralized with a dilute solution of sodium bicarbonate. The solutionwas then washed with distilled water until the water washings wereneutral- Percent Trimer 31.3 Tetramer 53.2 Pentamer 5.2

Distillable 89.7

The following refractive indices and boiling points were obtained forthe materials and the analytic data for the tetramer and pentamercompared favorably with those given in Example V:Gamma-carbethoxypropylmethylcyclopolysiloxanes- B.P. 0., 25 0., no 50microns Hg Cyclic trimcr".

1.4481-58' 215 Cyclic tetramer 1. 4462-8 240-280 Cyclic pentamer 1.4497800-840 Molecular weight: Found, 548, calculated, 522'.

In an analogous manner, the beta-carbethoxyethylmethylsiloxane cyclicscan be prepared from beta-cyanoethylmethylsiloxane cyclic tetramer. Thefollowing analytieal and physical data were obtained for the puretetramer:

[EtOOC(CI-l SiMeO] Boiling point: 205-210 C. (0.08 mm.)

Refractive index (n -)-1.4376

Molecular weight: Cal.-640.- Found 621 Saponification'No; Theoretical350. Found 365 Si(C H SiO Cal. 17.5%. Found 19.1%.

duce gamma-carbo 2-ethylbutoxypropylmethyldiethoxysilane: (CHARTREACTION 6) Gamma carbethoxypropylmethyldiethoxysilane (0.1

mol), 2-ethylbutanol (0.1 mol) and 'trifluoroacetic acid.

(1.0 gram) were mixed in a cubic centimeter roundbottom flaskfittedwithy-a reflux condenser, and heated.

therein. Ethanol began to reflux inthe head almost immediately. Thevolatile material was taken otf .at the heads and showed a refractiveindex very close to that of pure ethanol. After the ethanol wascollected (5.75;'cc.) the residue was thenheatedfor one hour at 100 C.under vacuum (less than-1 mm.) toremove the remaining 6th? anol and anyunreacted Z-ethylbutanolJ'Ihe residuewas then heated to C.. undervacuumto remove any unreacted gamma-carbethoxypropylmethyldiethoxysilane.

The end-product was subjected-.10 infrared analysis and found to contain:boththe ethoxy and carbo-2-ethylbutoxy groups.' I

Example X Transesterification "ofgamma-carbethoxypropylmethyldiethoxysilane with' 2-ethylbutanol in a 1:2molar ratio to produce gamma-carbow2-ethylbutoxypropylmethyldi-2-ethylbutoxysilane:

(CHART REACTION 6) Gamma carbethoxypropylmethyldiethoxysilane (0.1:

mol) and Z-ethylbutanol (0.2 mol) were mixed ina 25.0-

cubic centimeter round-bottomed flask fitted with a still.

head, and 1.0 gramzof trifluoroacetic acid was added.-

The flask was then heated. and refluxing started almost immediately. Thevolatiles were removed as formed. Fourteen (14) cubic centimeters ofvolatiles were collected (n '=1.'3645).. The residue was then strippedat 160 C. under vacuum to remove any unreacting starting silane. Theresidue thus obtained was subjected to infrared analysis and-found to besubstantially all gamma-.-carbo-2-ethylbutoxypropylmethyldi-Z-ethylbutoxysilane.

Example XI Transesterification ofgamma-carbethoxypropylmethyldiethoxysilane with n-butanol in a 1:2 molarratio to produce gamma-carbobutoxypropylmethyldibutoxysilane:

(CHART, REACTION 6) Gamma carbethoxypropylmethyldiethoxysilane 0.1 mol)and n-butanol (0.2 mol) ,were charged into a 250 cubic centimeterround-bottomed flask. fitted ,with a still-- head. Trifluoroaceticacid(1.0 gram) was added as catalyst, and thematerials were thereafterheatedto 100 C. for three days. Since a low. yield had been obtainedin aprevious run it was thought thatthe trifluoroacetic acid might be toovolatile, and, therefore, perfluoroglutaric.

acid (1.0.gram) was added and the heating continued fortwenty-four morehours. Theethanol formed was distilled;

over at atmosphericpressure. .On heatingthe pot to 300 C. at atmosphericpressure no. further volatile material was isolated. The residue wasthen stripped'under vacuum at.

160 C. to remove unreacted starting material.'Carbobutoxypropylmethyldibutoxysilane was identified by infrared.

analysis within the final residue.

Example XII Transesterification ofgamma-carbethoxypropylmethyldiethoxysilane with n-butanol in a 1:3 molarratio to produce gamma-carbobutoxypropylmethyldibutoxysilane:

(CHART REACTION 6) Gamn-ia carbethoxypropylmethyldiethoxysilane (0.1mol) and n-butanol (0.3 mol) were mixed in a 250 cubic centimeterround-bottom flask and trifluoroacetic acid (1.0 gram) was addedthereto. The flask was then fitted with a water-cooled still head andheated to 100 C. for 72 hours. Perfluoroglutaric acid was then added andthe mixture was heated to reflux for twenty-four hours during which timethe ethanol was distilled off. The reaction solution was then strippedunder vacuum (less than 1 mm.) at 100 C. to remove the remaining ethanoland unreacted n-butanol. The reaction solution was then stripped at 160C. under vacuum to remove the unreacted starting silane. The residuethus obtained was sholyn to begamma-carbobutoxypropylmethyldibutoxysilane by infrared analysis.

Example XIII Esterification of gamma-carboxypropylmethylsiloxane cyclictetramer with Ucon L'B-40:

(CHART REACTION 6) Gamma-carboxypropylmethylsiloxane cyclic tetramer, inamount 43.8 grams, Ucon LB-40 (a Ucon of about 300 molecular weightcontaining a terminal OH group), in amount 108 grams excess), 2.0 gramsof trifluoroaoetic acid, and 400 cubic centimeters of toluene werecharged into a one-liter flask with a Dean Stark Moisture Trap andrefluxed at 120 C. for 24 hours. At the end of this time, thetrifluoroacetic acid was neutralized and the material stripped undervacuum. The residue weighed 81 grams representing a 66 percent yield.The compound had a viscosity of 28 centistokes at C.

UTILITY REACTIONS The following additional examples are offered forpurposes of illustrating other reactions and select uses of typicalcompounds of the invention.

Example XIV Preparation of Amide ofBeta-Carbethoxyethyltriethoxysilane.--Beta-carbethoxyethyltriethoxysilaneof Example I (0.2 mole) and p-aminobenzoic acid (0.2 mole) were heatedin a flask fitted with a still head to 150 C. Ethanol began to refluxand the refluxing was continued for thirtytwo (32) hours. The ethanolwas then distilled off and the residue was vacuum stripped at 150-200"C. The resulting product was dissolved in chloroform, filtered and thenstripped of chloroform to yield a viscous resin-like material. Thismaterial proved to be an excellent ultraviolet absorber in the 2600 to3100 A. range. The percent transmission through a solution containing0.041 gram per liter of the product in ethanol within a cell of onecentimeter thickness is given below.

Wavelength (A) Percent transmission Example XV solution was heated to 90C. on a steam bath and a 2 percent by weight concentrated sulfuric acidsolution was added with stirring. The heating and stirring werecontinued for three (3) hours. The oil was then cooled to roomtemperature and sodium bicarbonate added to neutralize the sulfuricacid. The oil was then dissolved in diethyl ether and washed withdistilled water until the water washings were neutral to pH paper. Theether was then evaporated oil and cubic centimeters of toluene added.The toluene and any water remaining were then stripped off under vacuumat C. (three hours).

The resulting oil had a viscosity of 70.5 centistokes at 25 C.

Another oil containing five (5) percent by weight ofgamma-carbethoxypropylmethylsiloxy units and having a viscosity of 79centistokes at 25 C. was prepared from 5.0 grams of thegamma-carbethoxypropylmethylsiloxane cyclic tetramer of Example V, 87.3grams of octamethylcyclotetrasiloxane and 7.7 grams ofdodecamethylpentasiloxane.

Example XVI Preparation of a silicone-modified alkyd resin:

This example describes the preparation of an ethoxyendblocked siliconepolymer consisting of C H SiO (C5H5)2SlO, SlO 2 and units, and thecopolymerization of this silicone with an alkyd resin containing free OHgroups by transesterification.

For convenience, the cyano rather than the carbethoxy containingsiloxane was prepared first and the nitrile groups were then convertedto carbethoxy by the alcoholysis technique of the invention.

The starting materials were:

Moles Gamma-cyanopropyltrichlorosilane 0. 3 phenyltrichlorosilane 0.3Gamma-cyanopropylmethyldichlorosilane 0.2 diphenyldichlorosilane 0.3ethanol 0.24 water 1.175

The phenyltrichlorosilane and gamma-cyanopropyltrichlorosilane werecharged to a one-liter, three-necked flask equipped with droppingfunnel, stirrer, vacuum attachment and thermometer. The ethanol wasadded slowly with stirring and external cooling. The above difunctionalmonomers in 200 cubic centimeters of dry diethyl ether were then addedfollowed by slow addition of the water. The contents were stirred forone hour. This completed the primary polymer-forming step. The next stepwas directed to alcoholysis of the nitrile groups and furthercondensation of the materials. Two hundred (200) cubic centimeters ofdry ethanol were added and the ether stripped from the solution. Thesolution was then saturated with HCl and refluxed for six hours. A largequantity of ammonium chloride appeared as a precipitate during thereflux period. The solution was neutralized with sodium bicarbonate,filtered, diluted with 200 cubic centimeters of toluene, and finallystripped of both toluene and excess alcohol to yield a resinous productcontaining 90.8 percent solids. The product had a saponification numberof 147 and contained 21.6 percent (OC H as Si-OEt and COOEt units.

The above polymer was reacted with an alkyd resin prepared from thefollowing materials:

2-ethylhexoic acid: 2.4 moles Glycerine: 2.9 moles Dimethyltetephthalate: 2.24 moles Litharge, catalyst: 2 grams The silicone resin(40 grams) and alkyd resin (360 grams), in Solvesso 150 solvent (360grams), were heated in a distillation flask with stirring untilgellation appeared imminent. Ethanol was formed and 4.5 grams collected,the theoretical for complete transesterification of carbethoxy groupsbeing 8.8 grams. The resin was cooled and. 40 grams of isophorone wereadded. This resin solution had a viscosity of 205 centipoises andcontained 44.4 percent resin solids. It was used to coat glass cloth,aluminum and bonderized sheet steel. The dipped coatings cured to a hardflexible film at 200 C. which was not attacked by boiling water and onlyslightly by toluene. The heat stability of the films was excellent, infact, much better than could have been expected for a product this lowin silicone content. ,Glass cloth coated specimens were aged at 250 C.and showed good retention of their high initial dielectric strengthafter ten days at this temperature. In one test, the initial dielectricstrength was 1200 volts per mil and dropped to only 1160 volts per milafter 10 days at 250 C.

'Example XVII Preparation of the sodium salt and free acid ofbetacarboxyethylpolysiloxane by saponification and neutralization frombeta-carbethoxyethyltriethoxysilane:

Beta-carbethoxyethyltriethoxysilane, in amount 50 grams, was placedwithin a 500 cubic centimeter roundbottomed flask fitted with a refluxcondenser, and 10.5 grams of sodium hydroxide dissolved in 250 cubiccentimeters of water was added thereto. The mixture was then refluxedfor 72 hours. The ethanol was stripped oif and the residue was dissolvedin water. The material was then filtered to remove solid particles. Thewater solution was acidified with a ten percent hydrochloric acidsolution to give the free acid. A gel was formed. The gel was filteredoff and washed with water. The gelwas then dried in a vacuum oven at 100C. to yield a white solid which was identified as the desired free acidderivative.

Example XVIII Preparation of a carbethoxy-modified silicone resin bycohydrolysis of gamma-carbethoxypropyltriethoxysilane,phenyltriethoxysilane and diphenyldiethoxysilane:

The following ethoxy silanes, in the amounts indicated, were dissolvedin 100 milliliters of EtOH and charged into a one-liter, three-neckedflask fitted with stirrer, thermometer, and dropping funnel:

EtOOC(CH Si(OEt) 79.2 grams (0.3 mole) Si(OEt) 85.5 grams (0.3 mole)Si(O'Et) 110.4 grams (0.4 mole) Water was added to the mixture dropwisefrom the funnel, in amount 27.0 grams (10% excess-1.5 moles), and thetemperature rose from 18 C. to 21 C. Following the addition, heat wasapplied and a water condenser was put in place of the dropping funnel.The solution was refluxed for four (4) hours (80 C.). A clear lightgreen solution was obtained upon cooling. A sample was taken of thiscarbethoxy-modified resin, stripped of solvent, and heated at 150 C. for2 hours to yield a resin consisting of 99.8% solids. No gel formationoccurred. (n 1.5353). An infrared spectrum showed residual SiOH,CH(phenyl), CH CI-I COOC H Slip, Si SiO-Si.

Example XIX Preparation of beta carbethoxyethylmethylsiloxane cyclicpolymers by hydrolysis of beta-carbethoxyethylmethyldiethoxysilane:

Seventy grams (0.3 mole) of beta-carbethoxyethylmethyldiethoxysilane,300 milliliters of diethyl ether and 25 milliliters of water werecharged into a one-liter distillation flask fitted with a refluxcondenser and magnetic stirrer. The mixture was stirred at roomtemperature for 90 hours. Water and ether were removed under reduced and18} pressure to yield'49 grams yield).of a clear waterwhite liquid. Thehydrolyzate. was charged toa Hickman molecular still and distilled'underreduced pressure to yield the following three fractions:

(I) boiling point 70-80 C. (1.0-5.0) n 1.4379

(yield 13 grams); (II) boiling pointv 90.ll0 C. 2.0-5.0) n 1.4438

(yield 8.0 grams); and

(III) boiling point 1'10.-220 C. (2.0-5.0) n 1.4434

(yield 7.2 grams).

Fraction I was found'upon analysis-tobe a mixture of cyclic trimer andtetratmer,containingmostlytrimer but also some residual SiOH. Theanalytical-data for this fraction are as follows:

H 51 OEt Calculated 45. 0 7. 5 17. 5 28.1 (C HnSlOa) 41. 3 7. 9' 18.725. 2

XOCKJHQAiO wherein X is Cl, ZHN or MO; W is R, a-NH sub-- stitutedmonovalent hydrocarbon radical, or a COOH substituted monovalenthydrocarbon radical; M is an alkali metal; R is a monovalent hydrocarbonradical; and (b) has a value from 0 to.-l inclusive.

2. A siloxane amide asdefined'dn claim- 1 comprising units of theformula:

R'b zauoowm siio 1 i i 2 wherein Z is'R', a -NH substituted monovalenthydrocarbon radical, or a COOH substituted hydrocarbon radical; R is amonovalent hydrocarbon radical; and b has a value from 0 to 1 inclusive.

3. A siloxane acidchloride as defined. in claim 1 comprising units ofthe formula:

Rb oioowmhdio wherein R is a monovalent hydrocarbon radical; and b has avalue from 0 to 1 inclusive. v

4. A siloxane salt as defined in claim 1 comprising units having theformula:

R Mooowrnpdm 19 7. A siloxane consisting essentially ofunits as definedin claim 3 and units having the formula:

R SiO wherein d has a value from 1 to 3 inclusive, and R" is amonovalent hydrocarbon radical.

8. A siloxane consisting essentially of units as defined in claim 4 andunits having the formula:

R".isio

wherein d has a value from 1 to 3 inclusive, and R" is a monovalenthydrocarbon radical.

9. A siloxane as defined in claim 1 having the unit formula:

n G10c(CH,-,),si0

2 wherein R is a monovalnet hydrocarbon radical; and b has a value fromto 1 inclusive.

10. A siloxane as defined in claim 1 having the unit formula:

wherein Z is R, a NH substituted monovalent hydrocarbon radical, or aCOOH substituted hydrocarbon radical; R is a monovalent hydrocarbonradical; and b has a value from 0 to 1 inclusive.

11. A siloxane as defined in claim 1 having the unit formula:

wherein M is an alkali metal; R' is a monovalent hydrocarbon radical;and b has a value from 0 to 1 inclusive.

12. A siloxane as defined in claim 1 having siliconbonded alkoxy groups.

References Cited UNITED STATES PATENTS TOBIAS E. LEVOW, Primary ExaminerP. F. SHAVER, Assistant Examiner U.S. Cl. X.R.

10615 R, 287 SB; 117-124 E, 124 F, 126 AB, 126 GR, 126 GS, 126 GN;260448.2 N, 448.8 R, 46.5 E, 46.5 Y, 825

273x33 um'rm smizas PATENT OFFICE CERTIFICATE @F fiORREiITION Patent3.629309 Baud December 71 1071 v D.L. Bailey 5: V. B. Jex

It is certified that ez'mr azflpm'ra in the above-identified patent andthat said Letters Patent am hereby corrected as shown below:

Column 18, line 3]., "W is R should read -Z is R Signed and sealed this1st day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JRQ C. MARSHALL DANN Attesting Officer Commissioner ofPatents

